Background: Previous reports have questioned the validity of conventional solid state manometry, citing low interobserver agreement. The development of high-resolution manometry (HRM) catheters and graphic visualization software may offer advantages over conventional methods including less interobserver variability. The aim of this study was to compare interobserver variability between High Resolution (HRM) and Conventional Manometry (CM).Methods: 50 healthy volunteers underwent duplicate high resolution and conventional manometry studies performed on the same day in each subject. Studies were interpreted by 2 groups of three esophageal motility fellows (Group I:. 2005-6 vs. Group II: - 2007-8), Group I during the introduction of HRM into the diagnostic laboratory. All 6 individuals separately analyzed each of the 50 HRM and CM studies. Eleven outcome variables were measured for each technique:e including; lower esophageal sphincter (LES) resting pressure, residual pressure, abdominal length, total length, esophageal body contraction amplitudes in each of three segments and the percent simultaneous, failed and peristaltic contractions. Intraclass Correlation Coefficients (ICC) were calculated for the two groups of three and all six fellows separately. ICC > 0.75 was taken as good/excellent reproducibility. Results: Interobserver variability in CM was poor (ICC=0.07951-0.58124)in for every measured parameter with the exception of measurements of esophageal body pressures. Interobserver variability in HRM was excellent for measurements of LES resting and residual pressures, percent of failed contractions and esophageal body pressures at 5 and 10 cm but remained poor for measurement of LES lengths and % simultaneous waves (ICC=0.94406, 0.83196, 0.79124, 0.89381, 0.90312, and 0.21608, 0.2486, 0.18469 respectively). When values for the groups were averaged, interobserver agreement was superior in all measurements for HRM compared to CM and for Group II compared to Group I. Conclusion: Interobserver variability in the interpretation of high resolution manometry data is less than that of conventional manometry and improves with time suggesting an institutional learning curve. Further standardization of HRM analysis is needed.